org.apache.mahout.cf.taste.hadoop.pseudo
Class RecommenderReducer

java.lang.Object
  org.apache.hadoop.mapreduce.Reducer<VarLongWritable,org.apache.hadoop.io.NullWritable,VarLongWritable,RecommendedItemsWritable>
      org.apache.mahout.cf.taste.hadoop.pseudo.RecommenderReducer

public final class RecommenderReducer
extends org.apache.hadoop.mapreduce.Reducer<VarLongWritable,org.apache.hadoop.io.NullWritable,VarLongWritable,RecommendedItemsWritable>

The Reducer which takes as input the user IDs parsed out by the map phase, and for each unique user ID, computes recommendations with the configured Recommender. The results are output as RecommendedItemsWritable.

See Also:

RecommenderJob

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

org.apache.hadoop.mapreduce.Reducer.Context

Constructor Summary

RecommenderReducer()

Method Summary

protected void	reduce(VarLongWritable key, Iterable<org.apache.hadoop.io.NullWritable> values, org.apache.hadoop.mapreduce.Reducer.Context context)
protected void	setup(org.apache.hadoop.mapreduce.Reducer.Context context)

Methods inherited from class org.apache.hadoop.mapreduce.Reducer

cleanup, run

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RecommenderReducer

public RecommenderReducer()

Method Detail

setup

protected void setup(org.apache.hadoop.mapreduce.Reducer.Context context)
              throws IOException

Overrides:

setup in class org.apache.hadoop.mapreduce.Reducer<VarLongWritable,org.apache.hadoop.io.NullWritable,VarLongWritable,RecommendedItemsWritable>

Throws:

IOException

reduce

protected void reduce(VarLongWritable key,
                      Iterable<org.apache.hadoop.io.NullWritable> values,
                      org.apache.hadoop.mapreduce.Reducer.Context context)
               throws IOException,
                      InterruptedException

Overrides:

reduce in class org.apache.hadoop.mapreduce.Reducer<VarLongWritable,org.apache.hadoop.io.NullWritable,VarLongWritable,RecommendedItemsWritable>

Throws:

IOException

InterruptedException